Technical Field
The present invention relates to a non-contact wireless communication coil which can perform non-contact power transmission and non-contact wireless communication and a portable wireless terminal including the non-contact wireless communication coil.
Description of the Related Art
For example, portable wireless terminals including mobile phone terminals and smart phones which have a non-contact wireless communication (so-called radio frequency identification (RFID)) function, such as a near field communication (NFC) function including FeliCa (registered trademark), are being widespread. For example, an electronic money function and a ticket function are implemented by this type of non-contact wireless communication.
In addition, in recent years, a portable wireless terminal with a function of transmitting power in a non-contact manner to change a battery (non-contact charging) has been in use. Examples of the non-contact power transmission type include an electromagnetic induction type and a magnetic field resonance type. In general, a coil in a power supplier is opposite to a coil in a power receiver to transmit power.
In the portable wireless terminal with the non-contact charging function, in general, a charging coil is integrated with a battery pack. Therefore, if the battery pack is thinned in order to reduce the thickness of the terminal, battery capacity is reduced. In contrast, if the charging coil is provided separately from the battery pack, it may be necessary to solve the problems caused by the coexistence of the charging coil with a non-contact wireless communication coil in the portable wireless terminal with the non-contact wireless communication function.
Here, it is assumed that the non-contact wireless communication coil and the non-contact power transmission coil coexist. As the related art in which two coils are provided, for example, PTL 1 discloses a wireless card in which a first coil forming an antenna for power waves and a second coil forming an antenna for data waves are arranged so as to form a double ring. According to this structure, the first coil and the second coil are less likely to be covered with the fingers of the hand which holds the wireless card and it is possible to make the reception conditions of the two coils substantially equal to each other.